Airbag arrangements have been state of the art within motor vehicle design and construction for a considerable time and, in addition to the safety belts which are already known, are a further component of the safety system intended to prevent vehicle occupants from coming into contact with the vehicle body structure or other vehicle components in the event of a collision.
Multi-chamber airbag systems in which different chambers of the airbag are assigned to certain body areas of the vehicle occupants, have proven worthwhile. The individual chambers can include different volumes and internal pressures if a crash should occur, to account for the different load-bearing capacity of the body areas of the occupants.
For example, an airbag is disclosed in DE 198 50 448 A1, which includes two airbags formed so as to be separate from one another and which are linked to a gas generator by means of a guide device for dividing the gas stream between the airbags. The guide device surrounds the circumference of the gas generator and includes outflow openings for filling the airbags. In order to be able to inflate the airbags independently of one another with a certain volume of gas, it is proposed that the guide device be provided with throttle elements for control of the gas flow. A particular disadvantage of this arrangement is the difficulty of the manufacturing process and its associated cost, resulting from the complexity of the guide device. In addition, this airbag arrangement is relatively large in size, requires a large amount of material and is therefore relatively heavy.
In addition, a side airbag is disclosed in U.S. Pat. No. 6,349,964 B1 in the form of an airbag unit which includes a multi-chamber system. The actual airbag of the airbag unit is divided into two inflatable chambers by means of a dividing seam, with a single gas generator allocated to both chambers together. This gas generator is accommodated in a housing with separate inflow openings for filling the chambers with the propellant gas created by the gas generator. The inflow openings are provided with means to change their own open cross-section, for example electrically activated sliders or covers, in order to provide different pressures in the chambers. Here again, the high degree of complexity of the unit must be mentioned, resulting in an increased tendency of faults or disturbances.
It is the goal of the present invention to avoid the disadvantages of the state of the art described above and to create an airbag arrangement for a motor vehicle including two or more chambers which is simpler to manufacture, reasonably priced and not liable to faults and disturbances, and whose chambers can exhibit different internal pressures if the airbag unit is activated.